Mercedes-Benz and three commercial vehicle dealers are to pay fines totalling £2.6 million following an inquiry into market rigging.

The Office of Fair Trading (OFT) identified three separate breaches of competition law in relation to market sharing, price co-ordination and the exchange of commercially sensitive information.

The case, which centres on the distribution of Mercedes-Benz trucks and vans in the north of England and parts of Wales and Scotland, resulted in a fine of £1.5 million for the Daimler-owned company.

Ciceley, which has dealerships in Bolton, Blackburn, Carlisle and Dumfries, was fined £659,675, while the penalties for Enza Motors of Warrington, Stoke, Trafford Park and Manchester and North Wales-based Road Range were £347,000 and £115,000 respectively. A further dealer, Yorkshire-based Northside, avoided a fine as it provided evidence of collusion in return for immunity.

The OFT said two of the breaches related to the distribution of vans involving Ciceley and Northside and Ciceley and Road Range over a two-year period starting in early 2008.

The third breach involved the distribution of trucks between December 2009 and the following January and related to Ciceley, Enza, Mercedes-Benz and Road Range.

Ali Nikpay, OFT senior director of cartels, said: "These cases send a clear signal that the OFT will take firm action against companies that collude to deny customers the benefit of fair competition regardless of the size of the firms involved or geographic scope of the investigation.

"These examples also underline that the OFT can uncover cartels even in cases where the businesses involved do not blow the whistle, as well as being a concrete illustration of the benefits of businesses acting quickly and co-operating at the earliest opportunity so as to qualify for immunity from fines."

A Mercedes-Benz UK spokesman said: "We have reached a settlement with the OFT for one infringement of competition law relating to its recent investigation into the company and three of its commercial vehicle dealers operating in northern England and Wales. Mercedes-Benz regrets the incident and has learned a lot from it. The company has strengthened its internal controls, and every member of staff participates in comprehensive and ongoing integrity training programmes. The company and its staff have fully co-operated with the investigators over the past three years."

The spokesman went on: "This thorough OFT investigation took three years to complete, and the agreed settlement with Mercedes-Benz UK relates to one meeting held in late 2009. The settlement figure, based on company turnover, is £1.49 million. The settlement reached with the OFT draws the investigation into this matter to a close. Mercedes-Benz takes its responsibilities under competition law seriously and has taken all appropriate steps to ensure all its staff comply fully with the law."